Two-dimensional pyramid filter architecture

ABSTRACT

Embodiments of a two-dimensional pyramid filter architecture are described.

RELATED APPLICATIONS

[0001] This patent application is related to U.S. patent applicationSer. No. 09/754,684, titled “Multiplierless Pyramid Filter,” filed Jan.3, 2001, by Tinku Acharya; U.S. patent application Ser. No. ______ ,titled “Two-Dimensional Pyramid Filter Architecture,” (attorney docket042390.P11275), filed Mar. 26, 2001, by Tinku Acharya; U.S. patentapplication Ser. No. ______ , titled “Pyramid Filter,” (attorney docket042390.P11211), filed Mar. 28, 2001, by Tinku Acharya; and concurrentlyfiled U.S. patent application Ser. No. ______ , titled “Two-DimensionalPyramid Filter Architecture,” (attorney docket 042390.P11277), filedMarch ______ , 2001, by Tinku Acharya, all assigned to the assignee ofthe presently claimed subject matter and herein incorporated byreference.

BACKGROUND

[0002] This disclosure is related to pyramid filters.

[0003] In image processing it is often desirable to decompose an image,such as a scanned color image, into two or more separate imagerepresentations. For example, a color or gray-scale document image canbe decomposed into background and foreground images for efficient imageprocessing operations, such as enhancement, compression, etc., as are attimes applied in a typical photocopying machine or scanner device. Inthis context, this operation is often referred to as a descreeningoperation. This descreening is also sometimes applied to remove halftonepatterns that may exist in an original scanned image. For example, thesehalftone patterns may cause objectionable artifacts for human eyes ifnot properly removed. The traditional approach for this decomposition ordescreening is to filter the color image in order to blur it. Theseblurred results are then used to assist in determining how much to blurand sharpen the image in order to produce the decomposition. Typicallythis blurring can be achieved using a “symmetric pyramid” filter.Symmetric pyramid finite impulse response (FIR) filters are well-known.

[0004] One disadvantage of this image processing technique, however, isthat the complexity increases many fold when a number of pyramid filtersof different sizes are applied in parallel in order to generate multipleblurred images, to apply the technique as just described. A brute forceapproach for this multiple pyramid filtering approach is to use multipleFIR filters in parallel, as illustrated in FIG. 1. Such an approachdemonstrates that the design and implementation of fast “symmetricpyramid filtering” architectures to generate different blurred images inparallel from a single source image may be desirable.

[0005] The numbers provided in parenthesis for each FIR block in FIG. 1represents the pyramid filter of corresponding length. For example, (1,2, 1) are the filter coefficients for a symmetric pyramid finite impulseresponse (FIR) filter of order or length 3. Likewise, (1, 2, 3, 2, 1)are the coefficients for an FIR pyramid filter of order 5, (1, 2, 3, 4,3, 2, 1) are the coefficients for an FOR filter of order 7, and soforth.

[0006] Unfortunately, the approach demonstrated in FIG. 1 hasdisadvantages. For example, inefficiency may result from redundantcomputations. Likewise, FIR implementations frequently employ multipliercircuits. While implementations exist to reduce or avoid the use ofmultipliers, such as with shifting and summing circuitry, that may thenresult in increased clocking and, hence, may reduce circuit through-put.A need, therefore, exists for improving pyramid filteringimplementations or architectures.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Subject matter is particularly pointed out and distinctly claimedin the concluding portion of the specification. The claimed subjectmatter, however, both as to organization and method of operation,together with objects, features, and appendages thereof, may best beunderstood by reference of the following detailed description when readwith the accompanying drawings in which:

[0008]FIG. 1 is a block diagram illustrating a brute force approach toimplementing a finite impulse response (FIR) multiple pyramid filteringarchitecture;

[0009]FIG. 2 is one embodiment of a one-dimensional multiplierlesspyramid filter;

[0010]FIG. 3 is one embodiment of a two-dimensional pyramid filterarchitecture;

[0011]FIG. 4 is a table/matrix showing an example of a matrix that mayresult from implementing a two-dimensional pyramid filter architecture,such as one that may be implemented by the embodiment of FIG. 3;

[0012]FIG. 5 is a table/matrix showing an example of a two-dimensionalsignal that may be operated upon by a two-dimensional pyramid filterarchitecture;

[0013]FIG. 6 is a table/matrix showing an example of applying aone-dimensional pyramid filter kernel both row-wise and column-wise;

[0014]FIG. 7 is the table/matrix of FIG. 6 for k=9;

[0015]FIG. 8 is a table/matrix showing the result of applying aone-dimensional pyramid filter to the rows of a two-dimensional inputsignal sample matrix; and

[0016]FIG. 9 is a table/matrix showing the result of applying aone-dimensional pyramid filter to the columns of a two-dimensional inputsignal sample matrix.

DETAILED DESCRIPTION

[0017] In the following detailed description, numerous specific detailsare set forth in order to provide a thorough understanding of theclaimed subject matter. However, it will be understood by those skilledin the art that the claimed subject matter may be practiced withoutthese specific details. In other instances, well-known methods,procedures, components and circuits have not been described in detail inorder so as not to obscure the claimed subject matter.

[0018] As previously described, pyramid filtering, in particular,symmetric pyramid filtering, may be employed in connection with colorimages or color image processing in order to decompose or descreen theimage, such as into a background and foreground image, for example.Although the claimed subject matter is not limited in scope in thisrespect, in such a context, pyramid filtering architectures that reducecomputational complexity or processing and/or hardware cost areparticularly desirable. Likewise, implementations that aremultiplerless, that is do not specifically employ multiplication in theimplementation, are also desirable usually because such implementationsor embodiments are cheaper to implement than those that employ orinclude multiplier circuits.

[0019] Although the claimed scope is not limited in scope in thisrespect, FIG. 2 illustrates an embodiment 200 of a one-dimensionalpyramid filter, such as described in more detail in aforementioned U.S.patent application Ser. No. 09/754,684, titled “Multiplierless PyramidFilter,” by T. Acharya (attorney docket no. 042390.P10722), filed onJan. 3, 2001. Embodiment 200 comprises a unified multiplierless cascadedsymmetric pyramid filtering architecture to generate a multiple numberof filtered output signal streams for a series or sequence of pyramidfilters having different orders, the generation of the output signalstreams occurring in parallel. In this particular embodiment, although,again, the claimed subject matter is not limited in scope in thisrespect, a filtered output signal stream is produced on every clockcycle for each pyramid filter of a different order being implemented.Therefore, in addition to being computationally efficient, thisparticular embodiment produces good results in terms of throughput.However, as previously indicated, this particular embodiment implementsa one-dimensional pyramid filter.

[0020]FIG. 2 is understood in the context of specific notation. Forexample, an input source signal, X, may be designated as follows:

X=(x ₀ , x ₁ , . . . , x _(i−2) , x _(i−1) , x _(i) , x _(i+1) , x_(i+2), . . . )

[0021] In digital or discrete signal processing, filtering may beexpressed as a convolution, {circle over (x)}, of the input signal, X,and a filter, F, in this context a digital filter of finite length,referred to here as a finite impulse response (FIR) filter. Therefore,the filtered output signal stream is indicated as follows:

Y=X{circle over (x)}F

[0022] As previously described, the particular embodiment in FIG. 2employs pyramid filters. These filters are typically implemented usingdigital filters of lengths or orders that are odd, such as 3, 5, 7, 9,etc. Odd numbers or orders, in this context, may be expressed in theform 2N−1, where N is a positive integer greater than two, for example.Some examples of such digital filters are as follows:

[0023] F₃=(1 , 2, 1)

[0024] F₅=(1, 2, 3, 2, 1)

[0025] F₇=(1, 2, 3, 4, 3, 2, 1)

[0026] F₉=(1, 2, 3, 4, 5, 4, 3, 2, 1)

[0027] F_(M)=(1, 2, 3, . . . ,N, . . . 3, 2, 1) (where, in this context,M=2N−1)

[0028] For the foregoing filters, the filtered output signals or outputsignal streams may be represented as follows:

[0029] B³=X{circle over (x)}F₃=(b₀ ³, b₁ ³, . . . , b_(i−1) ³, b_(i) ³,b_(i+1) ³, . . . ) result of input signal X filtered by F₃

[0030] B⁵=X{circle over (x)}F₅=(b₀ ⁵, b₁ ⁵, . . . , b_(i−1) ⁵, b_(i) ⁵,b_(i+1) ⁵, . . . ) result of input signal X filtered by F₅

[0031] B⁷=X{circle over (x)}F₇=(b₀ ⁷, b₁ ⁷, . . . , b_(i−1) ⁷, b_(i) ⁷,b₁₊₁ ⁷, . . . ) result of input signal X filtered by F₇

[0032] B⁹=X{circle over (x)}F₉=(b₀ ⁹, b₁ ⁹, . . . , b_(i−1) ⁹, b_(i) ⁹,b_(i+1) ⁹, . . . ) result of input signal X filtered by F₉

[0033] B^(M)=X{circle over (x)}F_(M)(b₀ ^(M), b₁ ^(M), . . . , b_(i−1)^(M), b_(i) ^(M), b_(i+1) _(M), . . . ) result of input signal Xfiltered by F_(M)

[0034] An alternate way to empirically represent these filtered outputsignal samples is as follows:

b _(i) ³ =x _(i−1)+2x _(i) +x _(i+1)

b _(i) ⁵ =x _(i−2)+2x _(i−1)+3x _(i)2x _(i+1) +x _(i+2)

b _(i) ⁷ =x _(i−3)+2x _(i−2)+3x _(i−1)+4x _(i)+3x _(i+1)+2x _(i+2) +x_(i+3)

b _(i) ⁹ =x _(i−4)+2x _(i−3)+3x _(i−2)+4x _(i−1)+5x _(i)+4x _(i+1)3x_(i+2)+2x _(i+3) +x _(i+4)

[0035] Likewise, by introducing what is referred to, in this context, asstate variables, the above expressions may be re-expressed as follows:

b _(i) ³ =x _(i) +s _(i) ³,

where

s _(i) ³ =x _(i−1) +x _(i) +x _(i+1)

b _(i) ⁵ =b _(i) ³ +s _(i) ⁵,

where

s _(i) ⁵ =x _(i−2) +x _(i−1) +x _(i) +x _(i+1) +x _(i+2)

b _(i) ⁷ =b _(i) ⁵ +s _(i) ⁷,

where

s ₁ ⁷ =x _(i−3) +x _(i−2) +x _(i−1) +x _(i) x _(i+1) +x _(i+2) +x _(i+3)

b _(i) ⁹ =b _(i) ⁷ +s _(i) ⁹,

where

s _(i) ⁹ =x _(i−4) +x _(i−3) +x _(i−2) +x _(i−1) +x _(i) x _(i+1) +x_(i+2) +x _(i+3) +x _(i+4)

[0036] Hence, the desired pyramid filter may be expressed as follows:

B ³ =X+S ₃,

where

S ₃=(s ₀ ³ , s ₁ ³ , s ₂ ³ , . . . , s ¹⁻¹ ³ , s _(i) ³ , s _(i+1) ³, .. . )

B ⁵ =B ³ +S ₅,

where

[0037]S ₃=(s ₀ ⁵ , s ₁ ⁵ , s ₂ ⁵ , . . . , s _(i−1) ⁵ , s _(i) ⁵ , s_(i+1) ⁵, . . . )

B ⁷ =B ⁵ +S ₇,

where

S ₇=(s ₀ ⁷ , s ₁ ⁷ , s ₂ ⁷ , . . . , s _(i−1) ⁷ , s _(i) ⁷ , s _(i+1) ⁷,. . . )

B ⁹ =B ⁷ +S ₇,

where

S ₉=(s ₀ ⁹ , s ₁ ⁹ , s ₂ ⁹ , . . . , s _(i−1) ⁹ , s ⁹ , s _(i+1) ⁹, . .. )

[0038] A study of FIG. 2 illustrates that the computed output signalstreams, B₃, B₅, B₇, B₉, etc. of the pyramid filters shown in FIG. 2 areproduced by the embodiment illustrated.

[0039] The previous discussion of pyramid filters occurs in the contextof one-dimensional filtering; however, due at least in part to thesymmetric nature of such filters, it is possible to implement pyramidtwo-dimensional filtering instead of computing in a row-wise andcolumn-wise one-dimensional fashion that employs extra computationalsteps. If we represent the one-dimensional k-tap pyramid filter as${F_{k} = \begin{bmatrix}1 & 2 & 3 & \cdots & \frac{k - 1}{2} & \cdots & 3 & 2 & 1\end{bmatrix}},$

[0040] the corresponding two dimensional pyramid filter F_(kxk) may bederived as shown in FIG. 6. In FIG. 7, we have shown the two-dimensionalpyramid filter kernel for k=9. Assuming a two-dimensional input signal,e.g., signal samples, having the form shown in FIG. 5, FIG. 4 is a tableillustrating a matrix that may result, here a two-dimensional filteredsignal sample output matrix, P^(kxk), in which the two dimensional inputsignal sample matrix is filtered using two-dimensional pyramid filterkernel F_(kxk).

[0041] The matrix shown in FIG. 8 may result from applying aone-dimensional k-tap pyramid filter in every row of the two-dimensionalinput signal sample matrix and the matrix shown in FIG. 9 may resultfrom applying a one-dimensional k-tap pyramid filter in every column ofthe two-dimensional input signal sample matrix. The matrix in FIG. 4 mayresult from applying the two-dimensional (k×k) tap filter to the twodimensional input signal sample matrix or, alternatively, it may resultfrom applying the one-dimensional k-tap pyramid filter row-wise and thenfollowed by column-wise. Applying this approach to generate filteredsignal samples outputs P^(1×3), P^(3×1), and P^(3×3), produces thefollowing relationships:

P _(i,j) ^(1×3) =s _(i,j−1)+2s _(i,j) +s _(i,j+1)

P _(i,j) ^(3×1) =s _(i−1,j)+2s _(i,j) +s _(i+1,j)

P _(i,j) ^(3×3) =s _(i−1,j−1)+2s _(i−1,j) +s _(i−1,j+1)+2s _(i,j−1)+4s_(i,j)+2s _(i,j+1) +s _(i+1,j−1)+2s _(i+1,j) +s _(i+1,j+1)

[0042] Generating filtered signal samples outputs P^(1×5), P^(5×1), andP^(5×5), produces the following relationships:

P _(i,j) ^(5×1) =s _(i−2,j)+2s _(i−1,j)+3s _(i,j)2s _(i+1,j) +s _(i+2,j)

P _(i,j) ^(1×5) =s _(i,j−2)+2s _(i,j−1)+3s _(i,j)+2s _(i,j+1) +s_(i,j+2)

P _(i,j) ^(5×5)=(s _(i−2,j−2)+2s _(i−2,j−1)+3s _(i−2,j)+2s _(i−2,j+1) +

[0043] s_(i−2,j+2))+(2s _(i−1,j−2)+4s _(i−1,j−1)+6s _(i−1,j)+4s_(i−1,j+1)+2s _(i−1,j+)(3s _(i,j−2)+6s _(i,j−1)+9s _(i,j)+6s _(i,j+1)+3s_(i,j+2))+(2s _(i+1,j−2)+4s _(i+1,j−1)+6s _(i+1,j)+4s _(i+1,j+1)+2s_(i+1,j+2))+(s _(i+2,j−2)+2s _(i+2,j−1)+3s _(i+2,j)+2s _(i+2,j+1) +s_(i+2,j+2))

[0044] Likewise, generating filtered signal samples outputs P^(7×1),P^(1×7), and P^(7×7), produces the following relationships:

P _(i,j) ^(7×1) =s _(i−3,j)+2s _(i−2,j)+3s _(i−1,j)+4s _(i,j)+3s_(i+1,j)+2s _(i+2,j) +s _(i+3,j)

P _(i,j) ^(1×7) =s _(i,j−3)+2s _(i,j−2)+3s _(i,j−1)+4s _(i,j)+3s_(i,j+1)+2s _(i,j+2) +s _(i,j+3)

P _(i,j) ^(7×7)=(s _(i−3,j−3)+2s _(i−3,j−2)+3s _(i−3,j−1)+4s _(i−3,j)+

[0045]3 s _(i−3,j+1)+2s _(i−3,j+2) +s _(i−3,j+3))+(2s _(i−2,j−3)+4s_(i−2,j−2)+6s _(i−2,j−1)+8s _(i−2,j)+6s _(i−2,j+1)+4s _(i−2,j+2)+2s_(i−2,j+3))+(3s _(i−1,j−3)+6s _(i−1,j−2)+9s _(i−1,j−1)+12s _(i−1,j)+9s_(i−1,j+1)+6s _(i−1,j+2)+3s _(i−1,j+3))+(4s _(i,j−3)+8s _(i,j−2)+12s_(i,j−1)+16s _(i,j)+12s _(i,j+1)+8s _(i,j+2)+4s _(i,j+3))+(3s_(i+1,j−3)+6s _(i+1,j−2)+9s _(i+1,j−1)+12s _(i+1,j)+9s _(i+1,j+1)+6s_(i+1,j+2)+3s _(i+1,j+3))+(2s _(i+2,j−3)+4s _(i+2,j−2)+6s _(i+2,j−1)+8s_(i+2,j)+6s _(i+2,j+1)+4s _(i+2,j+2)+2s _(i+2,j+3))+(s _(i+3,j−3)+2s_(i+3,j−2)+3s _(i+3,j−1)+4s _(i+3,j)+3s _(i+3,j+1)+2s _(i+3,j+2) +s_(i+3,j+3))

[0046] Mathematical manipulation may be employed to produce thefollowing:

P _(i,j) ^(7×7)=(P _(i−1,j−1) ^(5×5) +P _(i−1,j+1) ^(5×5) +P _(i+1,j−1)^(5×5) +

[0047] P_(i+1,j+1) ^(5×5))−(P _(i,j−1) ^(7×1) +P _(i,j+1) ^(7×1) +P_(i−1,j) ^(1×7) +P _(i+1,j) ^(1×7)) −(s _(i−1,j−1) +s _(i−1,j+1) +s_(i+1,j−1) +s _(i+1,j+1))   [1]

[0048] Equation [1] above illustrates that a direct two-dimensionalpyramid filter architecture of order 2N−1, in this case where N is four,may potentially be implemented using either four two-dimensional pyramidfilters of order [2(N−1)−1], that is five, or one two-dimensionalpyramid filter of order [2(N−1)−1] using four signal sample matricesP_(i−1,j−1) ^(5×5), P_(i−1,j+1) ^(5×5), P_(i+1,j−1) ^(5×5), P_(i+1,j+1)^(5×5) and four one-dimensional pyramid filters of order 2N−1, hereseven, the filters being row-wise and column-wise, in this example. FIG.3 is a schematic diagram illustrating such an embodiment, although, ofcourse, the claimed subject matter is not limited in scope to thisparticular implementation or embodiment. For example, the output signalsamples corresponding to those produced by four two-dimensional pyramidfilters of order [2(N−1)−1], here order five where N is four, may notnecessarily be produced by two-dimensional pyramid filters. As just oneexample, these output signals may be produced using one-dimensionalpyramid filters. One such filter is shown in FIG. 2, although, again,additional approaches to producing the output signals for thearchitecture shown in FIG. 3 may also be employed.

[0049]FIG. 3 illustrates an integrated circuit (IC), 300, although, ofcourse, alternative embodiments may not necessarily be implemented on asingle integrated circuit chip. IC 300 includes a two-dimensionalpyramid filter architecture of an order 2N−1, where N is a positiveinteger greater than three, here four, in operation, is capable ofproducing, on respective clock cycles, at least the following. Pyramidfiltered output signals are produced corresponding to output signalsproduced by four one-dimensional pyramid filters of order 2N−1, again,seven in this example where N is four, 330, 340, 350, and 360 in FIG. 3.Pyramid filtered output signals are also produced corresponding tooutput signals produced either by four two-dimensional pyramid filtersor one two-dimensional pyramid of order [2(N−1)−1] or five here, where Nis four, using signal sample matrices P_(i−1,j−1) ^(5×5), P_(i−1,j+1)^(5×5), P_(i+1,j−1) ^(5×5), P_(i+1,j+1) ^(5×5). These output signals aresummed by adder 310 in FIG. 3. Likewise, the respective output signalsin this two dimensional pyramid filter architecture implementation, inthe implementation in FIG. 3, for example, the output signals of 330,340, 350, and 360, are summed on respective clock cycles of the twodimensional pyramid filter architecture, by adder 370 in FIG. 3. Adder380 sums the output signals of 310, 370, and 390. Of course, FIG. 3 isjust one possible example of an implementation and the claimed subjectmatter is not limited in scope to this or to another particularimplementation.

[0050] For example, N is not limited to four. Likewise, the pyramidfiltered output signals that correspond to output signals produced by atwo-dimensional pyramid filter are not limited to being implemented byone-dimensional pyramid filters or to two-dimensional pyramid filters.Likewise, as previously indicated, if one-dimensional filters areemployed, then the filters are not limited to the implementationapproach described in aforementioned U.S. patent application Ser. No.09/754,684, titled “Multiplierless Pyramid Filter,” filed Jan. 3, 2001,by Tinku Acharya, or in aforementioned U.S. patent application Ser. No.,titled “Pyramid Filter,” (attorney docket 042390.P11211), filed on Mar.28, 2001, by Tinku Acharya. For example, one-dimensional pyramid filtersother than multiplierless pyramid filters may be employed. Likewise,depending on the implementation, different numbers of such pyramidfilters and different orders of such pyramid filters may be employed.For example, the output signals may be combined or processed in a way toproduce pyramid filtered output signals corresponding to pyramid filtersof a different number, dimension, or order.

[0051] It will, of course, be understood that, although particularembodiments have just been described, the claimed subject matter is notlimited in scope to a particular embodiment or implementation. Forexample, one embodiment may be in hardware, whereas another embodimentmay be in software. Likewise, an embodiment may be in firmware, or anycombination of hardware, software, or firmware, for example. Likewise,although the claimed subject matter is not limited in scope in thisrespect, one embodiment may comprise an article, such as a storagemedium. Such a storage medium, such as, for example, a CD-ROM, or adisk, may have stored thereon instructions, which when executed by asystem, such as a computer system or platform, or an imaging system, forexample, may result in an embodiment of a method in accordance with theclaimed subject matter being executed, such as an embodiment of a methodof filtering or processing an image or video, for example, as previouslydescribed. For example, an image processing platform or an imagingprocessing system may include an image processing unit, a video or imageinput/output device and/or memory.

[0052] While certain features of the claimed subject matter have beenillustrated and described herein, many modifications, substitutions,changes and equivalents will now occur to those skilled in the art. Itis, therefore, to be understood that the appended claims are intended tocover all such modifications and changes as fall within the true spiritof the claimed subject matter.

APPENDIX A

[0053] William E. Alford, Reg. No. 37,764; Farzad E. Amini, Reg. No.42,261; William Thomas Babbitt, Reg. No.39,591; Carol F. Barry, Reg. No.41,600; Jordan Michael Becker, Reg. No.39,602; Lisa N. Benado, Reg. No.39,995; Bradley J. Bereznak, Reg. No. 33,474; Michael A. Bernadicou,Reg. No.35,934; Roger W. Blakely, Jr., Reg. No. 25,831; R. Alan Burnett,Reg. No. 46,149; Gregory D. Caldwell, Reg. No.39,926; Andrew C Chen,Reg. No. 43,544; Thomas M. Coester, Reg. No. 39,637; Donna Jo Coningsby,Reg. No. 41,684; Florin Conrie, Reg. No. 46,244; Dennis M. deGuzman,Reg. No. 41,702; Stephen M. De Klerk, Reg. No. P46,503; Michael AnthonyDeSanctis, Reg. No.39,957; Daniel M. De Vos, Reg. No. 37,813; Justin M.Dillon, Reg. No. 42,486; Sanjeet Dutta, Reg. No. P46,145; Matthew C.Fagan, Reg. No. 37,542; Tarek N. Fahmi, Reg. No. 41,402; GeorgeFountain, Reg. No.37,374; James Y. Go, Reg. No. 40,621; James A. Henry,Reg. No. 41,064; Willmore F. Holbrow III, Reg. No. P41,845; Sheryl SueHolloway, Reg. No.37,850; George W Hoover II, Reg. No. 32,992; Eric S.Hyman, Reg. No.30,139; William W. Kidd, Reg. No.31,772; Sang Hui Kim,Reg. No. 40,450; Walter T. Kim, Reg. No. 42,731; Eric T. King, Reg. No.44,188; Erica W. Kuo, Reg. No. 42,775; George B. Leavell, Reg. No.45,436; Kurt P. Leyendecker, Reg. No. 42,799; Gordon R. Lindeen III,Reg. No. 33,192; Jan Carol Little, Reg. No. 41,181; Robert G. Litts,Reg. No.46,876; Julio Loza, Reg. No. P47,758; Joseph Lutz, Reg.No.43,765; Michael J. Mallie, Reg. No.36,591; Andre L. Marais, under 37C.F.R. § 10.9(b); Paul A. Mendonsa, Reg. No. 42,879; Clive D. Menezes,Reg. No. 45,493; Chun M. Ng, Reg. No. 36,878; Thien T. Nguyen, Reg. No.43,835; Thinh V. Nguyen, Reg. No. 42,034; Dennis A. Nicholls, Reg. No.42,036; Daniel E. Ovanezian, Reg. No. 41,236; Kenneth B. Paley, Reg.No.38,989; Gregg A. Peacock, Reg. No. 45,001; Marina Portnova, Reg. No.P45,750; Michael A. Proksch, Reg. No. 43,021; William F. Ryann, Reg.44,313; James H. Salter, Reg. No. 35,668; William W. Schaal, Reg.No.39,018; James C. Scheller, Reg. No.31,195; Jeffrey S. Schubert, Reg.No. 43,098; George Simion, Reg. No. P47,089; Jeffrey Sam Smith, Reg.No.39,377; Maria McCormack Sobrino, Reg. No. 31,639; Stanley W.Sokoloff, Reg. No. 25,128; Judith A. Szepesi, Reg. No.39,393; Vincent P.Tassinari, Reg. No. 42,179; Edwin H. Taylor, Reg. No. 25,129; John F.Travis, Reg. No. 43,203; Joseph A. Twarowski, Reg. No. 42,191; Kerry D.Tweet, Reg. No. 45,959; Mark C. Van Ness, Reg. No.39,865; Thomas A. VanZandt, Reg. No. 43,219; Lester J. Vincent, Reg. No. 31,460; Glenn E. VonTersch, Reg. No. 41,364; John Patrick Ward, Reg. No. 40,216; Mark L.Watson, Reg. No. P46,322; Thomas C. Webster, Reg. No. P46,154; andNorman Zafman, Reg. No. 26,250; my patent attorneys, and Raul Martinez,Reg. No. 46,904, my patent agents; of BLAKELY, SOKOLOFF, TAYLOR & ZAFMANLLP, with offices located at 12400 Wilshire Boulevard, 7th Floor, LosAngeles, Calif. 90025, telephone (310) 207-3800, and Alan K. Aldous,Reg. No.31,905; Robert D. Anderson, Reg. No.33,826; Joseph R. Bond, Reg.No. 36,458; Richard C. Calderwood, Reg. No. 35,468; Paul W. Churilla,Reg. No. P47,495; Jeffrey S. Draeger, Reg. No. 41,000; Cynthia ThomasFaatz, Reg No. 39,973; Sean Fitzgerald, Reg. No. 32,027; John N.Greaves, Reg. No. 40,362; John F. Kacvinsky, Reg No. 40,040; Seth Z.Kalson, Reg. No. 40,670; David J. Kaplan, Reg. No. 41,105; Charles A.Mirho, Reg. No. 41,199; Leo V. Novakoski, Reg. No. 37,198; NaomiObinata, Reg. No.39,320; Thomas C. Reynolds, Reg. No.32,488; Kenneth M.Seddon, Reg. No. 43,105; Mark Seeley, Reg. No.32,299; Steven P. Skabrat,Reg. No.36,279; Howard A. Skaist, Reg. No. 36,008; Steven C. Stewart,Reg. No.33,555; Raymond J. Werner, Reg. No. 34,752; Robert G. Winkle,Reg. No. 37,474; Steven D. Yates, Reg. No. 42,242, and Charles K. Young,Reg. No. 39,435; my patent attorneys, Thomas Raleigh Lane, Reg. No.42,781; Calvin E. Wells; Reg. No. P43,256, Peter Lam, Reg. No. 44,855;Michael J. Nesheiwat, Reg. No. P47,819; and Gene I. Su, Reg. No. 45,140;my patent agents, of INTEL CORPORATION; and James R. Thein, Reg. No.31,710, my patent attorney; with full power of substitution andrevocation, to prosecute this application and to transact all businessin the Patent and Trademark Office connected herewith.

1. An integrated circuit comprising: a two-dimensional pyramid filterarchitecture of an order 2N−1, where N is a positive integer greaterthan three; said two dimensional pyramid filter architecture of order2N−1, in operation, capable of producing, on respective clock cycles, atleast the following: pyramid filtered output signals corresponding tooutput signals produced by four one-dimensional pyramid filters of order2N−1; and pyramid filtered output signals corresponding to outputsignals produced either by four two-dimensional pyramid filters or onetwo-dimensional pyramid filter of order [2(N−1)−1] using signal samplematrices of order [2(N−1)−1]; wherein the respective output signals insaid two dimensional pyramid filter architecture are summed onrespective clock cycles of said two dimensional pyramid filterarchitecture.
 2. The integrated circuit of claim 1, wherein N is four;and wherein said two dimensional pyramid filter architecture of orderseven, in operation, capable of producing, on respective clock cycles,the pyramid filtered output signals corresponding to output signalsproduced either by four two-dimensional pyramid filters or onetwo-dimensional pyramid of order five using four signal sample matricesP_(i−1,j−1) ^(5×5), P_(i−1,j+1) ^(5×5), P_(i+1,j−1) ^(5×5), P_(i+1,j+1)^(5×3), the pyramid filtered output signals being produced by aplurality of one-dimensional pyramid filters.
 3. The integrated circuitof claim 2, wherein said one-dimensional pyramid filters comprise asequence of scalable cascaded multiplerless operational units, each ofsaid operational units capable of producing a different order pyramidfiltered output signal sample stream.
 4. The integrated circuit of claim2, wherein said one-dimensional pyramid filters comprise other thanone-dimensional multiplierless pyramid filters.
 5. The integratedcircuit of claim 2, wherein said two dimensional pyramid filterarchitecture of order seven, in operation, capable of producing, onrespective clock cycles, the pyramid filtered output signalscorresponding to output signals produced either by four two-dimensionalpyramid filters or one two-dimensional pyramid of order five using foursignal sample matrices P_(i−1,j−1) ^(5×5), P_(i−1,j+1) ^(5×5),P_(i+1,j−1) ^(5×5), P_(i+1,j+1) ^(5×5), the pyramid filtered outputsignals produced by a plurality of one-dimensional pyramid filters beingproduced by eight one-dimensional pyramid filters of order five.
 6. Theintegrated circuit of claim 5, wherein, of the eight one-dimensionalpyramid filters of order five, four are applied row-wise and four areapplied column-wise.
 7. The integrated circuit of claim 5, wherein saidtwo dimensional pyramid filter architecture of order seven, inoperation, capable of producing, on respective clock cycles, the pyramidfiltered output signals corresponding to output signals produced by fourtwo-dimensional pyramid filters of order five, the pyramid filteredoutput signals produced by a plurality of one-dimensional pyramidfilters being produced by eight one-dimensional multiplierless pyramidfilters of order five.
 8. The integrated circuit of claim 7, wherein, ofthe eight one-dimensional pyramid filters of order five, four areapplied row-wise and four are applied column-wise.
 9. The integratedcircuit of claim 2, wherein said two dimensional pyramid filterarchitecture of order seven, in operation, capable of producing, onrespective clock cycles, the pyramid filtered output signalscorresponding to output signals produced by four two-dimensional pyramidfilters of order five, the pyramid filtered output signals produced by aplurality of one-dimensional pyramid filters being produced by otherthan one-dimensional multiplierless pyramid filters.
 10. The integratedcircuit of claim 1, wherein N is four; said two dimensional pyramidfilter architecture of order seven, in operation, being capable ofproducing, on respective clock cycles, at least the following: outputsignals produced by four two-dimensional pyramid filters of order five.11. The integrated circuit of claim 1, wherein said two dimensionalpyramid filter architecture of order seven, in operation, capable ofproducing, on respective clock cycles, the pyramid filtered outputsignals corresponding to output signals produced by four two-dimensionalpyramid filters of order five, the pyramid filtered output signals beingproduced by one or more two-dimensional pyramid filters other than fourtwo-dimensional pyramid filters.
 12. A method of filtering an imageusing a two-dimensional pyramid filter architecture of order 2N−1, whereN is a positive integer greater than three, said method comprising:summing, on respective clock cycles of said two dimensional pyramidfilter architecture, the following: pyramid filtered output signalscorresponding to output signals produced by four one-dimensional pyramidfilters of order 2N−1; and pyramid filtered output signals correspondingto output signals produced either by four two-dimensional pyramidfilters or one two-dimensional pyramid filter of order [2(N−1)−1] usingsignal sample matrices of order [2(N−1)−1].
 13. The method of claim 12,wherein N is four; pyramid filtered output signals corresponding tooutput signals produced either by four two-dimensional pyramid filtersor one two-dimensional pyramid filter of order [2(N−1)−1] using signalsample matrices of order [2(N−1)−1] comprising output signals producedby four two-dimensional pyramid filters of order five.
 14. The method ofclaim 12, wherein N is four; and wherein the pyramid filtered outputsignals corresponding to output signals produced either by fourtwo-dimensional pyramid filters or one two-dimensional pyramid filter oforder five using four signal sample matrices P_(i−1,j−1) ^(5×5),P_(i−1,j+1) ^(5×5), P_(i+1,j−1) ^(5×5), P_(i+1,j+1) ^(5×5) comprisepyramid filtered output signals produced by a plurality ofone-dimensional pyramid filters.
 15. The method of claim 14, whereinsaid one-dimensional pyramid filters comprise a sequence of scalablecascaded multiplerless operational units, each of said operational unitscapable of producing a different order pyramid filtered output signalsample stream.
 16. An article comprising: a storage medium, said storagemedium having stored thereon instructions, that, when executed result infiltering an image using a two-dimensional pyramid filter architectureof order 2N−1, where N is a positive integer greater than three, by:summing, on respective clock cycles of said two dimensional pyramidfilter architecture, the following: pyramid filtered output signalscorresponding to output signals produced by four one-dimensional pyramidfilters of order 2N−1; and pyramid filtered output signals correspondingto output signals produced either by four two-dimensional pyramidfilters or one two-dimensional pyramid filter of order [2(N−1)−1] usingsignal sample matrices of order [2(N−1)−1].
 17. The article of claim 16,wherein N is four; pyramid filtered output signals corresponding tooutput signals produced either by four two-dimensional pyramid filtersor one two-dimensional pyramid filter of order [2(N−1)−1] using signalsample matrices of order [2(N−1)−1] comprising output signals producedby four two-dimensional pyramid filters of order five.
 18. The articleof claim 16, wherein N is four; and wherein the pyramid filtered outputsignals corresponding to output signals produced either by fourtwo-dimensional pyramid filters or one two-dimensional pyramid of orderfive using four signal sample matrices P_(i−1,j−1) ^(5×5), P_(i−1,j+1)^(5×5), P_(i+1,j−1) ^(5×5), P_(i+1,j+1) ^(5×5), comprise pyramidfiltered output signals produced by a plurality of one-dimensionalpyramid filters.
 19. The article of claim 18, wherein saidone-dimensional pyramid filters comprise a sequence of scalable cascadedmultiplerless operational units, each of said operational units capableof producing a different order pyramid filtered output signal samplestream.
 20. An image processing system comprising: an image processingunit to filter scanned color images; said image processing unitincluding at least one two-dimensional pyramid filter architecture; saidat least one two-dimensional pyramid filter architecture comprising: atwo-dimensional pyramid filter architecture of an order 2N−1, where N isa positive integer greater than three; said two dimensional pyramidfilter architecture of order 2N−1, in operation, capable of producing,on respective clock cycles, at least the following: pyramid filteredoutput signals corresponding to output signals produced by fourone-dimensional pyramid filters of order 2N−1; and pyramid filteredoutput signals corresponding to output signals produced either by fourtwo-dimensional pyramid filters or one two-dimensional pyramid filter oforder [2(N−1)−1] using signal sample matrices of order [2(N−1)−1];wherein the respective output signals in said two dimensional pyramidfilter architecture are summed on respective clock cycles of said twodimensional pyramid filter architecture.
 21. The system of claim 20,wherein N is four; pyramid filtered output signals corresponding tooutput signals produced either by four two-dimensional pyramid filtersor one two-dimensional pyramid filter of order [2(N−1)−1] using signalsample matrices of order [2(N−1)−1] comprising output signals producedby four two-dimensional pyramid filters of order five.
 22. The system ofclaim 20, wherein N is four; and wherein the pyramid filtered outputsignals corresponding to output signals produced either by fourtwo-dimensional pyramid filters or one two-dimensional pyramid of orderfive using four signal sample matrices P_(i−1,j−1) ^(5×5), P_(i−1,j+1)^(5×5), P_(i+1,j−1) ^(5{5), P_(i+1,j+1) ^(5×5), comprise pyramidfiltered output signals produced by a plurality of one-dimensionalpyramid filters.
 23. The system of claim 22, wherein saidone-dimensional pyramid filters comprise a sequence of scalable cascadedmultiplerless operational units, each of said operational units capableof producing a different order pyramid filtered output signal samplestream.